1. Field of the Invention
The present invention generally relates to a backlight module. More particularly, the present invention relates to a backlight module which can preserve the lamp thereof from external impact and loading.
2. Description of Related Art
The liquid crystal display (LCD) comprises a liquid crystal panel and a back light module. Since the liquid crystals inside the panel are incapable of emitting any light, the liquid crystal panel must be illuminated from below by a planar light source such as the one produced by the back light module. Hence, the back light module is an important component in any liquid crystal display. The back light module can be further categorized into a direct-type back light module and a side-type back light module according to the position of the light source. Due to the requirement of the brightness, an L-shaped lamp is adopted as the light source of the side-type back light module recently.
FIG. 1A is a partially perspective view illustrating a conventional backlight module, and FIG. 1B schematically illustrates a sectional view of the conventional backlight module along line I-I′ after assembled. Referring to FIGS. 1A and 1B, the backlight 100 comprises a light guide plate 110, an L-shaped lamp 120, a lower frame 150 and an upper frame 160. The light guide plate 110 has a light incidence plane 112, a light diffusion plane 114 and a light emergence plane 116. The L-shaped lamp 120 is disposed beside the light incidence plane 112 to provide light into the light guide plate 110 via the light incidence plane 112. The light can be diffused and reflected by the light diffusion plane 114 and then emerges from the light emergence plane 116. Accordingly, the light guide plate 110 transforms the linear light source into a uniform planar light source for a liquid crystal panel (not shown in drawings).
In addition, the lower frame 150 is used for carrying the light guide plate 110 and the L-shaped lamp 120. The upper frame 160 is fixed on the lower frame 150, and the upper frame 160 exposes the light emergence plane 116 of the light guide plate 110. Thus, the planar light source from the light emergence plane 116 can arrive the liquid crystal panel (not shown in drawings) disposed above the upper frame 160.
Referring to FIG. 1A, holders 122, 124, and 126 are adopted to cover the turning angle, the high voltage end and the low voltage end of the L-shaped lamp 120 to locate the L-shaped lamp 120 on an appropriate position. Nevertheless, the holder 122 may shift and expose the turning angle as moving the backlight module 100, and thus external impact or loading may damage the turning angle of the backlight module 100.
Besides, even though the holders 122, 124 and 126 cover the L-shaped lamp 120 exactly, that can prevent the L-shaped lamp 120 from only the impact and loading on the x-y plane but not the loading of the liquid crystal panel along z-axis. In other words, the weight of the liquid crystal panel causes impact or pressure to the L-shaped lamp 120 along z-axis in the assembling process of the liquid crystal panel and the backlight module 100 may lead to the damage of the L-shaped lamp 120. Therefore, means for preserving the lamp of the backlight from the external force has been an important issue in this field.